Subsea Engineering

Jee Ltd has been awarded phase two of a contract with Scottish Enterprise, which will see the leading independent multi-discipline subsea engineering and training firm undertake the demonstration of their innovative “U-tube” solution in Scottish tidal waters.

In September 2014, Jee secured a phase one contract with Scottish Enterprise, which involved a pioneering study for the marine energy industry in Scotland. The contract tasked companies with developing solutions for locating, securing, protecting and recovering electrical array cables for tidal energy installations.

Jee’s protection system, the “U-tube”, features a pipe fixed to a J-tube which is secured to the turbine foundations at each end of the pipe. The cable is then pulled vertically into one of the J-tubes and through the pipe using a pre-installed messenger and winch line. Once the cable is pulled in, connections are made to the turbine nacelles using wet-mate connections. The “U-tube” system provides the marine contractor with full control of the cable installation, which can be stopped and reversed if necessary offering a high level of flexibility. It also provides a wider weather window for the cable installation, which allowed Jee to overcome one of the biggest challenges of the project.

Neil Ferguson, Energy and Clean Technologies Senior Executive at Scottish Enterprise, said: “Finding safe and low-cost solutions in this field is a key requirement for the successful deployment and operation of the initial demonstration tidal arrays around Scotland. At the same time developing this new technology will be fundamental to the reduction of marine energy project costs over the longer term, and enabling the successful commercialisation of the industry. The demonstration phase of this project is a key next step in achieving that, and we look forward to working with both companies over the next few months.”

Jonathan McGregor, Head of Engineering at Jee, said: “We were one of five companies initially selected to develop innovative solutions for this exciting renewables project and one of only two contractors selected by Scottish Enterprise to deliver the practical demonstration of the proposed solution.”

Jee will be designing, manufacturing and delivering the “U-tube” in collaboration with the other contractor, Aquatera Ltd who are responsible for installation using their novel cable installation methods.

“Our highly skilled team are delighted to be demonstrating the solution we have developed for this challenging tidal energy project. With decades of experience in providing innovative subsea engineering services to the expanding renewables industry, combined with Aquatera’s expertise in installation, we are well placed to provide the best results for this pioneering tidal energy development.”

Ian Johnstone, Consultant at Aquatera, said: “Aquatera is very pleased to be selected for this important project. We have pulled together a high quality team to develop innovative cabling solutions. The key components of our solution are cost reduction and flexibility which are vital for the industry to fully develop the tidal resource we have around our shores. The process to get to this stage has involved some intense workshops and problem solving as well as detailed financial analysis. Over the coming months we will construct our chosen design and trial it in Orkney waters using the local supply chain. We are confident that we can prove our option can deliver the project objectives to the benefit of the whole industry.”

Joe Gransden, Lead Engineer at Jee, said ”Fast currents, narrow offshore working windows and rocky seabeds found at typical tidal energy sites make through-life management of cable operations and maintenance a key challenge for the industry. Jee’s “U-tube” concept addresses this challenge and provides full cable protection, ultimately resulting in increased reliability and a reduction in through-life costs”.